The invention relates generally to guiding catheters, and more particularly to adjustable length guiding catheters used to locate and cannulate the coronary sinus of a patient""s heart.
Guiding catheters are instruments that allow a physician to locate and cannulate vessels in a patient""s heart for performing various medical procedures, including venography and implanting of cardiac pacing devices. Cannulating heart vessels requires navigating a small diameter, flexible guide through the convoluted vasculature into a heart chamber, and then into a destination heart vessel. Once the destination heart vessel is reached, the catheter acts as a pathway for insertion of payloads into the vessel.
A commonly accessed destination vessel for cardiac pacing lead insertion is the coronary sinus. A pre-shaped guiding catheter is typically used to locate the coronary sinus ostium from the right atrium. There are numerous potential percutaneous access vessels that can be used for right atrium access. Common pathways include the left cephalic vein and the left subclavian vein. Depending on the patient anatomy and the pathway chosen, a specialized guiding catheter may be required.
Guiding catheter systems are typically configured with a profile and length that is optimized for the intended method of access. The contours of pre-shaped guiding catheters are generally fixed, and this is typically achieved in production by constraining the distal end within a shaping fixture while warming them until they assume the intended shape (i.e., by xe2x80x9cheat settingxe2x80x9d their polymer shaft).
A fixed shape catheter is adequate in many cases where the pathway is not significantly convoluted and the pathway does not deviate significantly between patients. In situations where structural anomalies or significant variations exist, use of a fixed shape catheter may require that the clinician stock multiple size and shapes of catheters to account for potential variations. Fixed shape catheters may require a time consuming trial and error process of inserting and removing different shapes until the destination vessel is successfully accessed. Further, the need to stock various sizes and shapes of guide catheters adds complexity and expense to the support of such procedures.
There is a need for an improved catheter assembly for accessing heart vessels that can dynamically account for anatomical variations and be adaptable for different methods of access. The present invention fulfills these and other needs, and addresses other deficiencies of prior art implementations and techniques.
The present invention is directed to a catheter assembly for cannulating a vessel of a patient""s heart. According to one embodiment of the invention, a catheter assembly includes a guide handle having a proximal end, a distal end, a lumen open at least at the distal end of the guide handle, and a stop member disposed within the lumen at a distal end of the guide handle. The catheter assembly further includes a catheter having a proximal end disposed within the lumen of the guide handle. The catheter includes a preformed distal end, and the catheter is longitudinally displaceable within the guide handle to adjust an exposed length of the distal end of the catheter. The stop member is engagable with the proximal end of the catheter to prevent the proximal end of the catheter from passing out of the guide handle. A locking mechanism is provided within the guide handle. The locking mechanism engages the guide handle with the catheter to selectably prevent and permit axial rotation between the guide handle and catheter while permitting longitudinal displacement of the catheter within the guide handle.
In one configuration, the locking mechanism includes a locking arrangement longitudinally disposed along at least a portion of the guide handle lumen. The catheter further includes a locking arrangement longitudinally disposed along at least a-portion of the proximal end of the catheter. The respective locking arrangements of the catheter and guide handle engage and disengage to respectively prevent and permit axial rotation between the catheter relative to the guide handle while permitting longitudinal displacement of the catheter within the guide handle.
The locking mechanism can be engagable during extension and retraction of the catheter within the guide handle. Alternatively, the locking mechanism can be engagable only during full extension and full retraction of the catheter within the guide handle.
In one configuration, the locking mechanism includes a locking arrangement of the guide handle and a locking arrangement of the catheter. The locking arrangement of the guide handle includes at least one longitudinal groove at each of the proximal and distal ends of the guide handle. The locking arrangement of the catheter includes at least one longitudinal key at the proximal end of the catheter. The locking arrangement of the guide handle and the locking arrangement of the catheter can be engagable only at respective limits of longitudinal extension and longitudinal retraction of the catheter within the guide handle.
In another arrangement, a length of at least a portion of the guide handle lumen defines a travel length. The locking mechanism includes at least one longitudinal groove provided along a wall of the lumen. The catheter includes a locking member, including at least one longitudinal key having a length at least as long as the travel length of the lumen.
In one configuration of a catheter assembly according to the present invention, the exposed length of the distal end of the catheter can be adjustable within a range of 0 centimeters and about 15 centimeters. A length of the catheter assembly can range between about 40 centimeters and about 60 centimeters.
A catheter assembly according to the present invention can further include at least one electrode located at the distal end of the catheter. At least one electrical conductor can be disposed within the catheter and coupled to the electrode(s).
Other configurations include an occlusion device connected to the distal end of the catheter. Also, a hemostasis mechanism can be connected to the proximal end of the guide handle.
In one configuration, a seal can be included between the lumen of the guide handle and the catheter. The seal can include a plurality of O-rings or a leaflet seal between the lumen of the guide handle and the catheter. The seal can include a gel material or a hydrogel material provided between the lumen of the guide handle and the catheter.
In one configuration, the catheter has a diameter ranging between about 8 French and about 10 French.
In another embodiment according to the present invention, a catheter assembly includes a guide handle having a distal end, a proximal end, a lumen open at the distal end of the guide handle, and a stop member disposed within the lumen at the distal end of the guide handle. A length of at least a portion of the lumen defines a travel length. The catheter assembly includes a catheter having a proximal end disposed within the lumen of the guide handle. The catheter further includes a preformed distal end. The catheter is longitudinally displaceable within the guide handle to adjust an exposed length of the distal end of the catheter by a maximum length corresponding to the travel length of the lumen. The stop member engages with the proximal end of the catheter to prevent the proximal end of the catheter from passing out of the guide handle.
In one configuration, the guide handle further includes a locking arrangement longitudinally disposed along at least a portion of the lumen. The catheter further comprises a locking arrangement longitudinally disposed along at least a portion of the proximal end of the catheter. The respective locking arrangements of the catheter and guide handle engage and disengage to respectively prevent and permit axial rotation between the catheter relative to the guide handle while permitting longitudinal displacement of the catheter within the guide handle. In one aspect, the respective locking arrangements of the guide handle and catheter are engagable during extension and retraction of the catheter within the guide handle. In another aspect, the respective locking arrangements of the guide handle and catheter are engagable only during full extension and full retraction of the catheter within the guide handle.
A configuration includes the locking arrangement of the guide handle having at least one longitudinal groove at each of the proximal and distal ends of the guide handle. The locking arrangement of the catheter has at least one longitudinal key at the proximal end of the catheter.
In another embodiment of the present invention, a method of inserting a payload into a coronary sinus of a patient""s heart involves providing a guide catheter. The guide handle includes a proximal end, a distal end, a lumen open at least at the distal end of the guide handle, and a stop member disposed within the lumen at a distal end of the guide handle. The guide catheter further includes a catheter having a proximal end disposed within the lumen of the guide handle. The catheter has a preformed distal end. The catheter is longitudinally displaceable within the guide handle to adjust an exposed length of the distal end of the catheter. The stop member of the guide handle is engagable with the proximal end of the catheter to prevent the proximal end of the catheter from passing out of the guide handle. A locking mechanism is provided within the guide handle. The locking mechanism engages the guide handle with the catheter to selectably prevent and permit axial rotation between the guide handle and catheter while permitting longitudinal displacement of the catheter within the guide handle.
The method further involves inserting the preformed distal end of the catheter through a venous pathway via an access vessel. Longitudinally displacing the catheter within the guide handle adjusts an exposed length of the distal end of the catheter and accounts for variability of the venous pathway. Locking the guide handle and axially rotating the guide handle directs the preformed distal end of the catheter for finding and cannulating the patient""s coronary sinus.
In one aspect of the method, a payload is advanced through the catheter to seat the payload into the coronary sinus after finding and cannulating the patient""s coronary sinus. The payload can include an implantable cardiac lead. In another aspect of the method, a contrast media is injected through the catheter for mapping blood vessels after finding and cannulating the patient""s coronary sinus.
The above summary of the present invention is not intended to describe each embodiment or every implementation of the present invention. Advantages and attainments, together with a more complete understanding of the invention, will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings.